# RIS First-Last-Seen
This data call provides information on when a prefix or ASN was first and last seen in RIS data.
The data generally goes back to 2000. For the recency of the data you can check the parameter "latest_time", which usually is not more than 8 hours behind real-time.
The "low_visibility" flag, which can be optionally included, shows if the data point was seen by a low or high number of peers.
GET /data/ris-first-last-seen/data.json?resource=193.0.20.0/23
# Parameters
| Key | Value | Info | Required |
|---|---|---|---|
| resource | Prefix, ASN | A prefix or ASN to be looked up. The output for ASNs distinguishes between how an ASN has been seen in RIS. This can be as either originating or not. Originating has the type set to "o". | Yes |
| include | more_specific, low_visibility_flag | This parameter defines additional data to be included. "more_specific" includes more specific IP ranges, which only works for prefix lookups. By default "more_specific" is not set as it makes the lookup slower. "low_visibility_flag" includes the flag to indicate low visibility. By default it is not included. | No |